1. Field
Embodiments relate to a secondary battery.
2. Description of the Related Art
A secondary battery may be manufactured in various shapes, e.g., cylindrical and polygonal. The secondary battery may include an electrode assembly formed by winding a band-shaped positive electrode plate, a band-shaped negative electrode plate, and a separator interposed between the positive and negative electrode plates into a jelly-roll structure. Alternatively, a secondary battery may be formed by laminating a plurality of positive electrode plates, negative electrode plates, and separators. The electrode assembly may be accommodated in a case and then a cap assembly having external terminals may be coupled to the case to complete the secondary battery.
The cap assembly may have an electrolyte injection hole to provide a passage for injecting electrolyte into the case. The cap assembly may also have a stopper fitted into the electrolyte injection hole to prevent the electrolyte in the case from leaking out.